CVE-2023-39322: Golang Go

High severity, CVSS 7.5. EPSS: 1.3% chance of exploitation in the next 30 days.

QUIC connections do not set an upper bound on the amount of data buffered when reading post-handshake messages, allowing a malicious QUIC connection to cause unbounded memory growth. With fix, connections now consistently reject messages larger than 65KiB in size.

Affected products

• Golang Go: from 1.21.0, before 1.21.1 (fixed in 1.21.1)

Published 2023-09-08. Last modified 2026-06-17.